A big one...

This is the merge of the forward-loop branch. The main change here is that call-forwards can no longer loop.
This is accomplished by creating a datastore on the calling channel which has a linked list of all devices
dialed. If a forward happens, then the local channel which is created inherits the datastore. If, through this
progression of forwards and datastore inheritance, a device is attempted to be dialed a second time, it will simply
be skipped and a warning message will be printed to the CLI. After the dialing has been completed, the datastore
is detached from the channel and destroyed.

This change also introduces some side effects to the code which I shall enumerate here:

1. Datastore inheritance has been backported from trunk into 1.4
2. A large chunk of code has been removed from app_dial. This chunk is the section of code
   which handles the call forward case after the channel has been requested but before it has
   been called. This was removed because call-forwarding still works fine without it, it makes the
   code less error-prone should it need changing, and it made this set of changes much less painful
   to just have the forwarding handled in one place in each module.
3. Two new files, global_datastores.h and .c have been added. These are necessary since the datastore
   which is attached to the channel may be created and attached in either app_dial or app_queue, so they
   need a common place to find the datastore info. This approach was taken in case similar datastores are
   needed in the future, there will be a common place to add them.


git-svn-id: http://svn.digium.com/svn/asterisk/branches/1.4@90735 f38db490-d61c-443f-a65b-d21fe96a405b

2 files changed, 42 insertions, 0 deletions

diff --git a/include/asterisk/channel.h b/include/asterisk/channel.h
index 7ee4bef11..d6c9063f9 100644
--- a/include/asterisk/channel.h
+++ b/include/asterisk/channel.h
@@ -118,6 +118,7 @@ extern "C" {
 #include "asterisk/stringfields.h"
 #include "asterisk/compiler.h"
 
+#define DATASTORE_INHERIT_FOREVER	INT_MAX
 
 #define AST_MAX_FDS		8
 /*
@@ -148,6 +149,7 @@ struct ast_generator {
 /*! \brief Structure for a data store type */
 struct ast_datastore_info {
 	const char *type;		/*!< Type of data store */
+	void *(*duplicate)(void *data); /*!< Duplicate item data (used for inheritance) */
 	void (*destroy)(void *data);	/*!< Destroy function */
 };
 
@@ -156,6 +158,7 @@ struct ast_datastore {
 	char *uid;		/*!< Unique data store identifier */
 	void *data;		/*!< Contained data */
 	const struct ast_datastore_info *info;	/*!< Data store type information */
+	unsigned int inheritance;	/*!Number of levels this item will continue to be inherited */
 	AST_LIST_ENTRY(ast_datastore) entry; /*!< Used for easy linking */
 };
 
@@ -575,6 +578,9 @@ struct ast_datastore *ast_channel_datastore_alloc(const struct ast_datastore_inf
 /*! \brief Free a channel datastore structure */
 int ast_channel_datastore_free(struct ast_datastore *datastore);
 
+/*! \brief Inherit datastores from a parent to a child. */
+int ast_channel_datastore_inherit(struct ast_channel *from, struct ast_channel *to);
+
 /*! \brief Add a datastore to a channel */
 int ast_channel_datastore_add(struct ast_channel *chan, struct ast_datastore *datastore);
 
diff --git a/include/asterisk/global_datastores.h b/include/asterisk/global_datastores.h
new file mode 100644
index 000000000..72edabac5
--- /dev/null
+++ b/include/asterisk/global_datastores.h
@@ -0,0 +1,36 @@
+/*
+ * Asterisk -- An open source telephony toolkit.
+ *
+ * Copyright (C) 1999 - 2007, Digium, Inc.
+ *
+ * Mark Michelson <mmichelson@digium.com>
+ *
+ * See http://www.asterisk.org for more information about
+ * the Asterisk project. Please do not directly contact
+ * any of the maintainers of this project for assistance;
+ * the project provides a web site, mailing lists and IRC
+ * channels for your use.
+ *
+ * This program is free software, distributed under the terms of
+ * the GNU General Public License Version 2. See the LICENSE file
+ * at the top of the source tree.
+ */
+
+/*! \file
+ * \brief globally accessible channel datastores
+ * \author Mark Michelson <mmichelson@digium.com>
+ */
+
+#ifndef _ASTERISK_GLOBAL_DATASTORE_H
+#define _ASTERISK_GLOBAL_DATASTORE_H
+
+#include "asterisk/channel.h"
+
+extern const struct ast_datastore_info dialed_interface_info;
+
+struct ast_dialed_interface {
+	AST_LIST_ENTRY(ast_dialed_interface) list;
+	char interface[1];
+};
+
+#endif